Condenser.



w. 1. MURbOCK.

CONDENSER. 7 APPLICATION FILED FEB. 7. 1911.

1,174,600. Patented Mar. 7,1916.

W/ IT/E5555- g3? ZU'JMu rdock WM 3'. MURDOCK, OF EVERETT, MASSACHUSETTS.

connnnsnn Specification of Letters Patent.

Patented Mar. 7, 1916.

Application filed February 7, 1911. Serial No. 607,196.

To all whom it may concern Be it known that I, WILLIAM J. MURnocK, of Everett, in thecounty of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Condensers, of which the following is a specification.

The present invention relates to anelectrical condenser adapted for any purpose to which a condenser may be put, but having especial reference to and particular design for use in the art of radiotelegraphy, in which present practice prescribes the employment of electrical energy at a compare duction of an electrical condenser suited for use in connection with electrical energy of high potential and high frequency, of a nature such that the internal losses in operation are reduced to a minimum: (0) the production of an electrical condenser adapted for use in connection with electrical energy of high potential and high frequency, of such a nature that the material in which the electrical strain is produced is strengthened physically and electrically by so associating the various parts that the resulting material is practically a unit. These objects are realized: (a) by the employment-of a specially prepared dielectric material in association with the necessary conductors, and (b) by the construction of the entire condenser with particular reference to the formation of the dielectric material therein, as a unit solid, every part of which is essentially, practically, and permanently integral with every other part thereof.

In the drawing accompanying this specification, I have illustrated a condenser in which the principles of my invention are embodied and by which the objects above noted are carried into efiect- It is to be understood that the condenser may be made in any form and that the particular form here illustrated is not essential, but is shown merely for illustration.

Figure 1 represents a side elevation of the I condensen' Fig. 2 is a plan view of the same. Fig. 3 is a section on line 33 of Fig. 1. F1g. 4 is a section on line 44: of Fig. 1.

The novel features ,of this invention whereby I secure-the desired results are hereinafter specified. I preferably employ a dielectric material composed of mica in a pulverulent or a granular state, intimately associated by a mechanical method of mixture with a binding gum of a resinous nature,-the combination being such that at a relatively high temperature the material is plastic, is adapted. to manipulation, formation, or compression at the pleasure of the operator, and at the lower temperatures, assumes physical characteristics similar to those of most solids. The statement that I employ a combination of granular mica and a resinous gum, capable of becoming plastic at a certain temperature is not intended to be a limitation of the invention. The use of any substance which may be pulverized, and which possesses the properties of an electrical dielectric, in combination with any material possessing similar electrical properties, and capable of assuming a plastic nature upon the application of heat, so that it may be manipulated, formed or compressed, may be considered within the scope of this invention. The original feature here-noted consists in the use of the specified combination, or of similar combinations, as a dielectric material in an electrical condenser adapted to high potential and high frequency oscillations of electrical energy. This material is formed into plates, which, in the finished condenser are put under compression, as later described. By such compression of the dielectric material I secure such intimate association of the ultimate particles of the original matter, that the nature of the matter is changed with reference to its power of withstanding the disruptive forces of the electrical strains to which it is subjected in operation, thus making possible the safe use of less bulky layers than would be possible in dielectric material of this nature not similarly treated.

must be such that it is capable of transmitill) ting through its ultimate particles, electrical energy at high potential in oscillatory form,

possess, depends upon the production 'of a state of electric strain within the dielectric, said strain being a condition, definitely dif- -ferent from the state ordinarily characterized as non-conductivity. Thus, the process of creating the state of strain, and the use of electrical expe'dients for the removal of said strain, implies a distinct and an individual use of the dielectric material, connoting the production of definite force lines within the dielectric, which force lines in their actions and interactions are adaptedtothe formation of electromagnetic Waves of known characteristics suitablevfor use in radiotelegraphy. It maytherefore be maintained that the employment of the specified material as a dielectric in a condenser suited for theproduction of electromagnetic waves used in radiotelegraphy is an undoubtedly novel, andj a hitherto uncontemplated use of such material distinctly different from the customary use of insulating materials in the electrical arts as non-conductors.

. The common of the more wi el usedcondensers implies the interleaving o the dielectric sheets with separated or separable conducting media, or conversely. By my method, I produce in f one operation, a necessary component of the condenser, comprising the necessary conductive material practically united to and embedded in the dielectric -material in such a fashion that the association between the dissimilar members is most intimate, and consequently most 'efli'cient, the requirements of a good condensenstipulating a most inti-J mate contact of the dissimilar members.

In the drawing a and b represent the electrically conductlve sheets of opposite sign respectively, which may e metallic plates, sheets of foil, wires, ribbons, or net work, or may have any other suitable form, .and are termed sheets for the purpose of detrio is indicated by 0. Conductors 03 lead from the sheets a beyond the boundaries of "the condenser into connection with a bind ing post 6, and similar conductors f lead from the sheets I) to a binding post 9 of opposite polarity. Said conductors may and preferably are, wires, strips, or ribbons laid against the sheets, but they may be integral tongues or extensions of the sheets. They may also be of any desired length and led inany desired way to the binding posts, which may be located wherever desired. It and-z represent metal plates in conductive $5 connection with the conductors d and f, re-

ractice in the manufacture spectively, and secured to the condenser by any desired means, as screws 7' and nuts la. The ends Z and m, adjacent to one another, of these plates are adapted to constitute terminals or poles between which is an air gap n. The width of this gap may be made such that the condenser will be discharged between the terminals before disruption of the dielectric can occur.

In the manufacture of a complete con- 'denser, I. assemble a sufiicient number of dielectric plates and layers or sheets of conducting material in alternation to secure a desired electrical capacity, at the same time placing suitable electrical conductors 'in so contact with predetermined conductive layers, in such a manner that the said conduc tors protrude beyond the plates of dielectric material, and form suitable terminals for the oscillatory condenser circuit. I then 5 subject the collection of plates and sheets to' a temperature sufiicient to render the dielectricmaterial plastic. The entire collection is then subjected to great pressure, being for that purpose inclosed within a suitable 9o mold, said pressure having two main results: (1) reducing the-bulk of the collection of plates orsheets, and (2) rendering the contiguous dielectric plates, in the special localities where they are in contact, apractical unit, at the same time effecting a merging or a coalitionof contiguous p'articles' throughout the entire. dielectric material, such a- Way that each and every particle is placed in close connection and in apposition with each and every contiguous particle of the entire dielectric. vThereby the edges of the adjacent dielectric plates extending beyond the associated conductive sheets are welded together, and the sheets are thus enveloped and surrounded by a unit mass of dielectric material without cracks or spaces or even portions of less dielectric strength adjacent to the planes of the sheets; with the result that the tendency to brushf electrical discharges (which occur with high frequency electrical oscillatory energy from exposed conductors having thin edges) is checked and nullified, and

t the internal losses in the condenser from scriptl'on and not of limitatlon. The dielecpaclty for capacity, smaller in bulk than any other condensers made in the desirable rectangular plate form which have come to my knowledge. Capacity for capacity, they occupy approximately one-fourth thespace of the ordinary and most commonly used- Leyden' jar equipment, and one-third that occupied by glass plate condensers of like purpose. An advantage beyond more reduction in bulk lies in the-physical strength of the completed condenser, which renders it superior to forms employing glass as a dielectric, particularly on ships where the likelihood of accidental breakage is the maximum, my condenser being practically unbreakable by ordinary means and therefore not requiring a case of any kind to protect it against breakage. The two advantages pointed out are incidental to a more important advantage, namely, that, my condenser shows a minimum of internal losses in operation, the ratio experimentally determined between mine and some of the leading types now in use being as low as one to four. Further advantages, which have been heretofore noted in the preparation of electrical condensers are also presented in my product, namely, in the increase of capacity resulting from the application of pressure, and the increase in 'dlelectric resistivity to the disruptive tendencies of the electric strain permeating the dielectric during the operation of the condenser. A last advantage may be noted that the dielectric which I employ is plastic in the commercial sense that it may be readily modeled, molded, formed, or compressed, and is thus suited for'the speedy and ecomonical production of eflicient condensers by the simplest processes.

What I claim and desire to secure by Letters Patent is: r

1. An electrical condenser comprising a plurality of layers of electrically conductive material embedded in an-enveloping dielectric material, said dielectric material being a solid and under molecular compression at the temperatures to,.which the condenser is subject in use, and being plastic at mate-' rially higher temperatures, said condenser being totally a self-sustaining solid possessmg intrinsic properties ofdensity, hardness, tenacity, and cohesion, and requiring no external confinin means. I 2. An electrical condenser having an enveloping dielectric material, a plurality of conductive layers alternately disposed with masses of said material, and protruding connection conductors held in contact with said layers by the intrinsic cohesive qualities of the enveloping dielectric material, said pro 'truding conductors being permanently united to their respective conductive sheets thereby.

electrical condenser having a plurality of layers of electrically conductive material embedded in an enveloping dielectric material, said dielectric material being a mechanical and chemical product of a mineral powder, and a vegetable gum, said combination of materials possessing dielectric properties and being capable of assuming a unit self-sustaining solid form of great cohesion, tenacity, and hardness upon successive applications of heat, pressure and cooling.

i. In a condenser, a unified, solid dielectric substance, between and around the several conductive layers, said dielectric substance being the compressed product of a plastic mixture of a mineral powder, and a vegetable gum,- substantially as described.

5. An electrical condenser comprising a plurality of layers of electrically conductive material and layers or plates of dielectric material, said conductive anddielectric layem being arranged in alternation with the conductive material embedded in the dielectric, and the dielectric layers being merged or welded together beyond and around the edges'of the conductive layers; said dielectric material being an intimate association or mixture of mica in a granular state with a-binding gum of a resinous nature, and being in such permanent state of compression that its dielectric strength is augmented.

6. An electrical condenser comprising an alternating series of conductive sheets and dielectric plates, said plates being of greater superficial area than said sheets and extending beyond the boundaries of the latter in all directions; said dielectric plates being of material which is plastic at temperatures higher than'those encountered by the contures and to be tough at low temperatures;

said dielectric plates being under high comgi'gssion and being welded together in the shed condenser. In testimony whereof I have afiixed my signature, in presence of two witnesses.

J. MURDOCK. Witnesses! Amen H. BROWN, P. W. Pazm'rr. 

